Security will be tight for this year's Detroit Free Press/Chemical Bank Marathon

Security will be tight for this year's Detroit Free Press/Chemical Bank Marathon

Jessica J. Trevino, Detroit Free Press

With that in mind, Aaron Velthoven, vice president of marketing for Michigan.com, said precautions are already being taken.

“Our major concern with the weather right now is the humidity,’’ said Velthoven. “The humidity can have an effect on how you run. With the high humidity, we’re trying to communicate to the runners that you really want to know your limits. You want to stay hydrated. We’re actually going to order and will have extra water and cups available across the race track because of the current humidity forecast. That’s the weather story at the moment.’’

Velthoven said he has kept an eye on Weather.com and it shows 75% to 80% humidity for Sunday’s race.